Abstract

Spatially resolved values of the Al‐Ga interdiffusion coefficient for p‐i‐n and n‐i‐p AlGaAs‐GaAs device structures are found to be nearly identical in magnitude, but to vary with position by a factor of 2 across a 1 μm thick multiple quantum well active region. These observations are in marked contrast with theoretical predictions given that the Fermi level to valence‐band energy separation changes by 0.7 eV across the intrinsic region and suggest that impurity‐free layer disordering does not provide the necessary uniformity in energy shift for photonicintegrated circuit fabrication in its present state of development.